1. Field of the Invention
The present invention relates to a vehicle driving assist system that can give a proper alarm to a driver in accordance with a forward gazing state of the driver.
2. Description of the Related Art
Recently various techniques of detecting the traveling environment in front of a vehicle by using an in-vehicle mounted camera or the like and performing alarm control for obstacles in front of the vehicle have been developed and practically used. Furthermore, a technique of giving a natural alarm in accordance with a driver's state under the above alarm control has been also proposed. For example, JP-A-2004-295472 discloses a mechanism of giving no alarm or giving a weak alarm for an obstacle located within a predetermined distance from a vehicle if the direction of the visual line of the driver is coincident with the direction to the obstacle concerned.
However, according to the technique disclosed in the above publication, only the direction along which the driver pays his/her attention (hereinafter referred to as “gazing direction”) is determined. Therefore, when the driver gives his/her visual line to an object other than the obstacle, it is impossible to estimate the distance from the driver to the object at which the driver gazes, and thus it is impossible to grasp whether the driver pays his/her attention to a near object or a far object. Therefore, when the driver pays attention to a far object, objects located at a short distance from the driver are out of driver's attention. Therefore, even when the direction of the driver's visual line is afterwards coincident with the direction to an obstacle located at a short distance due to the behavior of the obstacle concerned (the behavior of darting into the front side of the vehicle or the like), it is improper to output no alarm or output a weak alarm.